In the prior art, 3-Dimensional structures have been fabricated by braiding or winding of impregnated reinforcement members (fibers, tapes or filaments) on a mandrel, removing said fibers from said mandrel and placing the resulting tubes of wound fibers into a mold and curing the resin or other matrix material into a composite part.
Difficulty has been experienced in removing the tubes of fibers from the mandrel. This removal was usually accomplished by collapsing the mandrel and sliding off the tube of wound fibers. These tube structures could then be formed into "C" shaped beams. When "I" or "J" beams were required, a separate fabrication was necessary to produce the edge flange or angled portions of the structures.
It would be desirable if the wound fibers could be easily removed from the mandrel, and the layers of fibers parted for later insertion of additional fiber stiffners as desired. Further, to achieve greater structural integrity and continuity of fibers as well as ease of fabrication of the layers, the fibers should be deposited on a single mandrel and the fibers should run through the entire composite structure with the least possible discontinuity.